1. Field
The present invention relates to substrate processing apparatus and, more particularly, to a substrate bonding tool.
2. Brief Description of Related Developments
Consumers desire ever cheaper electrical and electronic devices. A major part of the cost in producing consumer electrical and electronic devices is the cost of the semiconductor devices that provide the very features that make the electronic devices so desired by consumers. Manufacturers of the semiconductor devices thus continue to seek ways to lessen manufacturing costs of the semiconductors. Increasing manufacturing throughput, thereby reducing unit cost, is one way semiconductor manufacturers seek to achieve their goal. By way of example, various types of semiconductor devices have an architecture formed by bonding more than one substrate or wafer to each other. Conventional bond tools generally perform the bond operation one wafer stack at a time. To improve throughput, some conventional bond tools have a cluster of bond chambers, each of which is capable of bonding a stack of wafers at a time. Though bond cluster tools do provide throughput improvements over non-cluster bond tools, it may be readily realized that conventional bond cluster tools are more costly than non-cluster tools due to the multiplicity of substantially identical components and systems in the cluster tool as well as the greater demands on the automated control system to perform the operation with the cluster tool. Further, conventional cluster tools suffer an inherent throughput penalty arising from the time spent in moving wafers to and from different tool chambers or modules (i.e. different destinations) when loading and unloading the tool. By comparison, in a non-cluster tool the movement of wafers is but to and from a single chamber or module (i.e. a common destination) when loading and unloading the tool, thereby eliminating repositioning of the transport apparatus for different transport paths with a commensurate reduction in transport times. The present invention overcomes the problems of conventional tools as will be described in greater detail below with reference to exemplary embodiments.